I don't understand your logic here, the son is getting full and sole benefit of home price appreciation + equity AND he is removing $120K from marital property. The argument about deposition is not valid, you don't need to answer hypothetical questions like future gifts to children, nor do you need to abide by any disclosure you made years ago. There is really no case 3 years later. Its not a silver bullet, the law has vested full authority to either partner in the marriage to use marital assets as they see fit during a marriage
No. The son is a renter. The Dad is getting the full benefit of rental income, appreciation, and equity. The son is paying $120k in rent. To say that that is removing it from marital property isn't exactly true. Why? Because the full $120k no longer exists. $46k of it is lost to mortgage interest. $10k(ish) to property taxes. $4k to insurance. That's $60k right there, or half. Is your intent to safeguard your money, or is it just to spite your spouse? Of the remaining $60k, only $20k will be coming back to the son with the house in the form of the equity portion of the mortgage payments. The other $40k is either still part of Dad's estate, or lost to the IRS in Dad's income tax from rental income. So you're paying $120k to get back $20k, plus <$40k in some separate future transfer. Say 3 more years of gifts under $15k to stay under the tax exempt gift level. Is that better than the son having bought the house initially?
Now the gift transfer. Dad may have tax liability on that gift. Depending on the size of Dad's estate, it could affect future gift ability, or estate taxes upon Dad's death. As far as the equity, in general on a gift of this type the basis on home price for the son will be the price Dad paid and not the FMV of the property at the time of gift while the gift amount deducted from Dad's estate will be the current FMV of the property. Which means that that equity may cause the son to pay higher capital gains tax on its future sale.
So in the end you are left with less than half of what you were shuffling off to Dad. Dad has probably lost money on the deal if he's returning the rental income. Son is probably on the hook for higher capital gains on the house.
And of course all of that is without taking into account the effect this type of move on the divorce itself. A contested divorce can be amazingly expensive. For a move like this to make any sense at all, your financial benefit has to outweigh the additional cost to litigate it in the divorce. You could very easily see yourself facing an $80k legal bill after the lawyers and accountants get done, all to "save" $60k. Is it still worth it? When instead of this scheme, you could have had a clear prenup and a less contentious and less expensive divorce?